Author: Will Kennerley

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Yaquina Head Seabird Monitoring: Mid-Summer 2023

Hello Everybody!

My name is Ricardo Rodriguez, I am the Education and Outreach intern at Yaquina Head Outstanding Natural Area through Environment for the Americas. I recently graduated from the University of California, Merced with a Bachelor’s degree in Biological Sciences. I am assisting Oregon State University’s Seabird Oceanography Lab’s research efforts to monitor the reproductive success of the Common Murres (Uria aalge), Brandt’s Cormorants (Urile penicillatus), and Pelagic Cormorants (Urile pelagicus). I have experience conducting avian point count surveys of urban songbirds in Northeast Los Angeles as a Community Climate Action Corps Fellow, but this my first taste of bird monitoring and nest tracking in my early career. I am very grateful for this opportunity to contribute to this long-term monitoring effort.

Per usual, the Common Murres have had a rocky season on Colony Rock. There were many eggs that were eaten or dropped by Western Gulls (Larus occidentalis) when the voracious Bald Eagles (Haliaeetus leucocephalus) would hunt for Murres. It has been very unfortunate seeing broken Murre eggs along Yaquina Head. Between the first monitored murre egg (June 12th) and our last recorded eagle disturbance (July 17th), we recorded more than 1.1 eagle disturbances per hour of observation and directly witnessed 73 eggs consumed by eagles and gulls during these events.  Eagle disturbances and predation of the Murres has have slowed down significantly since the middle of July, thankfully, thus allowing Murres to incubate any eggs that have not been destroyed .

Following disturbances from Bald Eagles, Western Gulls swoop in to feast on unprotected murre eggs. Photo credit: Ricardo Rodriguez.

Both adults of a Common Murre breeding pair incubate the egg. The incubation period can take anywhere from 28 to 37 days.  The first Murre chick was observed on July 19, 2023 on Seal Rock and this year is likely the latest median hatch date we’ve ever recorded (peak hatch this year was between July 28th and August 7th).  2018 was the previous record for latest median hatch date (~July 15th) at Yaquina Head, so the delay caused by predator disturbance this year was quite significant. As many as 26 Murre chicks have been recorded in our monitoring plots at Colony Rock alone, and we are hopeful to see many more on the other offshore islands that we have been observing.

Better late than never! Median hatch date for murre chicks is the latest we’ve ever recorded at Yaquina Head. Photo credit: Will Kennerley.

Adult Murres have been observed and photographed to bring their chicks lots of Smelt (Osmeridae) and Herring (Clupeidae ). We’ve also conducted our first of multiple dawn-to-dusk provisioning watches by which we estimate the rate at which adult murres provision their chicks.  We hope to fit in two more of these watches before weekly until more chicks fledge.  Some chicks have already fledged and their calls can sometimes be heard from the headland.  I have worked at Yaquina Head since the beginning of April; I have clearly seen less and less Murres attending the colony compared to the amount back in May.

Oregon State University PhD student Suzanne Winquist records a murre feeding its chick during one of our dawn to dusk provisioning watches. Photo credit: Will Kennerley.

We are nearing the end of our Pelagic and Brandt’s Cormorant monitoring efforts at Yaquina Head Following a total of 55 nests across the two species, we estimated that Pelagic and Brandt’s Cormorants fledged an average of 2.8 and 2.4 chicks per nest, respectively.  All in all, we estimated that more than 80% of all cormorant chicks that hatched eventually went on to fledge, among the highest we’ve recorded in the 16 years we’ve been monitoring cormorant productivity.  

It has been an absolute pleasure working with an amazing team of researchers.  Come visit us out at Yaquina Head!

— Ricky, Neci, Jacque, Mariam, and Will

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Yaquina Head Seabird Monitoring: 2023 Early Season Update

By Will Kennerley, Faculty Research Assistant

It’s once again summer on the Oregon Coast and that means the seabirds are back at Yaquina Head.  My name is Will Kennerley and I’m the newest faculty research assistant in the Seabird Oceanography Lab. Part of my work will include leading the monitoring fieldwork at Yaquina Head this year.  I spent the previous six summers working with seabirds in the Gulf of Maine, including two seasons of fieldwork for my Master’s, which I completed here at OSU in May.  I’m looking forward to applying this experience to Oregon’s large and diverse seabird populations.

Monitoring work at Yaquina Head began towards the end of May with the confirmation that Brandt’s and Pelagic Cormorants were both breeding here this year.  Pelagic Cormorants failed to breed successfully in 2022, so we were anxious to see how they would perform.  Much to our relief, at least 70 Pelagic Cormorant nests have been documented in Smuggler’s Cove, alone, and most have healthy clutches of four eggs. 

Our very first Pelagic Cormorant chick was observed on June 23rd and we’re hopeful that there will soon be many more!  As for Brandt’s Cormorants, we recorded our first chick back on June 16th and most Brandt’s nests so far have at least one hatched chick, with even more on the way!  It seems that the cormorants are off to a good start this year.

Most Pelagic Cormorants remain on eggs at the Smuggler’s Cove subcolony at Yaquina Head.  The first chicks for this species were noted in late June and many Pelagic Cormorant chicks will likely be hatching out over the next week.

In typical fashion, the situation for the Common Murres is a little less rosy.  Starting in the middle of June, murre eggs appeared in a slow trickle that was easily consumed by Western Gulls during the frequent eagle disturbances.  There were a couple troubling weeks in which our monitoring team would observe new nests in our monitoring plots during each visit without any of these eggs ever surviving until the following check, just two or three days later. 

This situation has improved somewhat during the last week, thankfully, and eggs are being laid in greater numbers; hopefully this bump in egg-laying can overwhelm the marauding gulls and allow some eggs to survive and develop.  Overall, I suspect murre productivity will be poor at Colony Rock, where I’ve seen as many six different Bald Eagles roosting at a time, but some of the smaller rocks around Yaquina Head provide better cover for the murres and have thus far avoided most of the disturbances and depredation.  Although the season is advancing rapidly, there’s still some time for murres to be at least somewhat successful – I’m not ready to be pessimistic just yet! If the murres do succeed in hatching some chicks, this year’s median chick hatch date will likely be the latest ever recorded at Yaquina Head.

The complex topography of “Stegosaurus” and the other smaller subcolonies at Yaquina Head may provide sufficient cover from aerial predators for at least a small number of murres to breed successfully.

This year we are also systematically monitoring breeding murres and cormorants at Pirate Cove in the town of Depoe Bay.  We’re employing the same protocols as at Yaquina Head, just with slightly less frequent visits.  While the situation at these two colonies is broadly similar, we’ve documented fewer eagle disturbances per hour of observation at Pirate Cove than at Yaquina Head so far.  Because of this, a small number of murre eggs have now been incubated for at least two weeks and I am hoping that murres at this colony will successfully produce at least a few chicks.

Also of note this year is the consistent Tufted Puffin sightings that we’ve had at Yaquina Head!  As many as three individuals have been observed at once, and we’ve seen the birds circle the murre colony numerous times over the course of some mornings.  One Tufted Puffin even landed on the backside of Colony Rock, where puffins once bred.  While there haven’t been any signs of a nesting attempt, our hopes are high for continued puffin activity throughout this season and next.

If you’re around at Yaquina Head in the mornings, come introduce yourself!  I’m typically joined by a great team comprised of Jacque (REU intern), Neci (Doris Duke scholar), and Ricardo (Environment for the Americas BLM/YHONA intern) and we’d be happy to say hello.

A Bald Eagle seizes an adult Common Murre at Pirate Cove.  This disturbance caused the rest of the colony to flee, leaving the eggs vulnerable to predation by Western Gulls (note the gull with its mouth full, just to the right of the eagle).